High frequency composite switch module

ABSTRACT

A radio frequency (RF) hybrid switch module includes an antenna duplexer integrated with a surface acoustic wave (SAW) filter used in a mobile communication device such as a cellular phone. The switch module handles a transmitted signal and received signal of different frequency bands. A parasitic inductance due to a mounting of the SAW filter is reduced, so that an attenuation characteristic at a low frequency of the SAW filter is improved. The RF hybrid switch module includes: a dividing circuit; a switching circuit; a low pass filter (LPF); an electrode for forming at least a portion of the dividing circuit, switching circuit, and the LPF; a laminated body including a dielectric layer having the electrode formed thereon; a SAW filter which is mounted on the laminated body, corresponds to plural frequency bands, and has a grounding port; a diode mounted on the laminated body for forming a portion the switching circuit, a grounding electrode formed in the laminated body, and a via-conductor directly connecting the grounding port of the SAW filter.

TECHNICAL FIELD

[0001] The present invention relates to a radio frequency (RF) hybridswitch module used in a mobile communication device such as a cellularphone.

BACKGROUND ART

[0002] A small, high-efficiency dividing circuit and antenna duplexerused in a mobile communication device such as a cellular phone have beenrecently demanded. A conventional circuit block diagram of a radiofrequency (RF) component such as the mobile communication device isshown in FIG. 11. FIG. 11 shows an antenna duplexer in a compositeterminal for a GSM system at 900 MHz band, which is used at a cellularphone in Europe, and a DCS system at 1.8 GHz band.

[0003] As shown in FIG. 11, the RF component includes antenna port 61,transmitting ports 62, 64, receiving ports 63, 65, control terminals 66,67, dividing circuit 68, switching circuits 69, 70 and low pass filters71, 78. Dividing circuit 68, being generally formed of a low pass filterand high pass filter, divides a received signal into a GSM band and aDCS band. Switching circuits 69, 70 switch between a transmitting signaland a received signal at respective bands.

[0004] The receiving ports are connected with respective band-passfilters, e.g., surface acoustic wave (SAW) filters 73, 74, for limitingreceiving bands. As shown in FIG. 12, antenna duplexer 76 and SAW filter77 are mounted individually on board 75 of the cellular phone, thusrequiring a large mounting area.

[0005] The cellular phone is recently required, for a furtherconvenience, to be small as well as to have a multi-band function andmore functions. An antenna duplexer responsive to the requirement isaccordingly demanded.

[0006] The above-mentioned antenna duplexer, since including the antennaduplexer and band-pass filter mounted individually on the board,requires a land and a space for connecting the duplexer with the filter.This makes a communication device including the antenna duplexer behardly small. Further, since the individual components are connectedwith each other, a signal is transmitted on the board. This creates aloss of the signal on the board, thus reducing a receiving sensitivityof the communication device.

[0007] The SAW filter used for the band-pass filter for limiting thereceiving band is influenced by a parasitic inductance produced betweena ground and a SAW resonator connected with the ground. That is, theinductance shifts an attenuation pole at a lower frequency in anattenuation band toward a lower frequency, and decreases an amount ofattenuation at the pole. The SAW filter, when being integrated with theantenna-duplexer formed in a laminated body, has a grounding portthereof coupled with a grounding terminal via a leading line and avia-conductor in the laminated body. As a result, a parasitic inductanceof the leading line reduces an attenuation amount at a lower frequencyof the SAW filter.

SUMMARY OF THE INVENTION

[0008] A radio frequency (RF) hybrid switch module includes an antennaduplexer used in a mobile communication device such as a cellular phone,and a surface acoustic wave (SAW) filter integrated therein. The modulehandles transmitted signals and received signals of different frequencybands. a parasitic inductance due to the mounting of the SAW filter isreduced, and the SAW filter has an improved attenuation characteristicat a lower frequency.

[0009] The RF hybrid switch module includes: a dividing circuit; aswitching circuit; a low pass filter (LPF); an electrode pattern formingat least a portion of the dividing circuit, switching circuit, and LPF;a laminated body including a plurality of dielectric layers, theelectrode pattern being formed on at least one of the dielectric layers;a surface acoustic wave (SAW) filter corresponding to the frequencybands, having a grounding port, being mounted on the laminated body; adiode mounted on the laminated body, for forming a portion of theswitching circuit; a grounding electrode formed in the laminated body;and a via-conductor directly connecting the grounding port of the SAWfilter.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010]FIG. 1 is a circuit block diagram of a radio frequency (RF) switchmodule in accordance with an exemplary embodiment of the presentinvention.

[0011]FIG. 2 is an equivalent circuit diagram of the module inaccordance with the embodiment.

[0012]FIG. 3 shows an outward appearance of the module in accordancewith the embodiment.

[0013]FIG. 4 is an exploded perspective view of the module in accordancewith the embodiment.

[0014]FIG. 5 is an exploded perspective view of another RF switch modulein accordance with the embodiment.

[0015]FIG. 6A is an equivalent circuit diagram of a surface acousticwave (SAW) filter in accordance with the embodiment.

[0016]FIG. 6B is a characteristic diagram of the SAW filter inaccordance with the embodiment.

[0017]FIG. 7 is a plan view showing a mounting condition and a terminalarrangement of the RF switch module in accordance with the embodiment.

[0018]FIG. 8 is a plan view showing a mounting condition and a terminalarrangement of the RF switch module in accordance with the embodiment.

[0019]FIG. 9 is a plan view showing a mounting condition and a terminalarrangement of the RF switch module in accordance with the embodiment.

[0020]FIG. 10 shows an internal structure of the RF switch module inaccordance with the embodiment.

[0021]FIG. 11 is a circuit block diagram of a conventional RF component.

[0022]FIG. 12 is the conventional RF component mounted on a board.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0023]FIG. 1 is a circuit block diagram of a radio frequency (RF) hybridswitch module in accordance with an exemplary embodiment of the presentinvention. The RF hybrid switch module is formed of a circuit shown inFIG. 1 and formed as a one-chip module. The module corresponds twofrequency bands (e.g. a GSM band as a first frequency band and a DCSband as a second frequency band), and can be used for dividing areceived signal and a transmitted signal in the GSM and DCS bandsbetween an antenna of a dual-band cellular phone.

[0024] The RF hybrid switch module operates in twotransmitting/receiving systems, e.g. a GSM system and a DCS system,having different frequency bands. The RF hybrid switch module includes:dividing circuit 8 for dividing a received signal into the firstfrequency band (the GSM band) and the second frequency band (the DCSband), and for mixing the signals; switch 9 for switching between atransmitted signal and a received signal of a firsttransmitting/receiving system (the GSM system); low pass filter (LPF) 11coupled with a transmitting line of switch 9; surface acoustic wave(SAW) filter 12 coupled with a receiving line of switch 9; switch 10 forswitching between a transmitted signal and a received signal of a secondtransmitting/receiving system (the DCS system); LPF 13 coupled with atransmitting line of switch 10; and SAW filter 14 coupled with areceiving line of switch 10.

[0025]FIG. 2 is an equivalent circuit diagram of the RF hybrid switchmodule. LPF 11 is formed of capacitors C1 through C3 and inductor L1.LPF 13 is formed of capacitors C14 and C15 and inductors L8 and L9.Switch 9 is formed of capacitors C4 through C8, inductors L2 through L5,and diodes D1 and D2. Switch 10 is formed of capacitors C16 through C20,inductors L10 through L13, and diodes D3 and D4. Dividing circuit 8 isformed of capacitors C9 through C12 and inductors L6 and L7.

[0026] A parallel resonant circuit formed of capacitor C10 and inductorL6 resonates approximately at the second frequency band, and a seriesresonant circuit formed of capacitor C13 and inductor L7 resonatesapproximately at the first frequency band.

[0027] Diode D2 and capacitor C8 series-resonate at a first transmittingfrequency, so that an impedance of a receiving side measured at anantenna terminal can be local-maximized by phase rotation of a π-typephase-circuit formed of capacitors C6 and C7 and inductor L4. As aresult, switch 9 for switching between transmitting and receiving can beformed with diodes D1 and D2.

[0028] Capacitor C4 and inductor L3 cancel a capacitance of turned-offdiode D1 at a first received frequency band. Inductor L2 is a chokeinductor, and capacitor C5 is a by-pass capacitor.

[0029] Diode D4 and capacitor C20 series-resonate at a secondtransmitting frequency, so that an impedance of a receiving sidemeasured at the antenna terminal can be local-maximized by phaserotation of a π-type phase-circuit formed of capacitors C18 and C19 andinductor L12. As a result, switch 10 for switching between transmittingand receiving can be formed with diodes D3 and D4.

[0030] Capacitor C16 and inductor L11 cancel a capacitance of turned-offdiode D3 at a second received frequency band. Inductor L10 is a chokeinductor, and capacitor C17 is a by-pass capacitor.

[0031]FIG. 3 shows an outward appearance of the RF hybrid switch moduleformed as a one chip module. A portion of the dividing circuits, LPFsand switching circuits are formed in a laminated body. Chip component16, e.g., a diode or a chip inductor, and SAW filter 15, which transmitsa signal in the first receiving band and the second receiving band, aremounted on laminated body 17.

[0032] Laminated body 17 is formed of laminated dielectric layers eachhaving a low dielectric constant (εr<10). In the laminated body, aninductor is formed of a meandered or spiral electrode pattern, and acapacitor is formed of electrodes facing each other. An input/outputelectrode and grounding electrode 18 are formed on the side of thelaminated body.

[0033]FIG. 4 is an exploded perspective view of the module shown in FIG.3. Laminated body 17 is divided into laminated bodies 17 a, 17 b and 17c as shown in FIG. 4. Grounding terminal 19 to 22 for mounting SAWfilter are directly connected with grounding electrode 28 formed onlaminated body 17 c through respective via-holes 23 a to 26 a formed inlaminated bodies 17 a and 17 b. As shown in FIG. 6A, this structurediscussed above reduces parasitic inductance 30 produced between aground and SAW resonator 29. As shown in FIG. 6B, a series resonantfrequency of SAW resonator 29 thus does not shift largely toward a lowerfrequency. This suppresses a shift of a frequency of an attenuation poleat a low frequency of the SAW filter, and a reduction of an attenuation.

[0034] In FIG. 4, grounding electrode 28 is formed on a bottom laminatedbody, however, in FIG. 5, grounding electrode 28 is formed on laminatedbody 17 d disposed near the top body. In this structure, via-holes 23 bto 26 b become shorter by a thickness of laminated body 17 b, thusreduces the parasitic inductance and restrains the attenuation reductionof the SAW filter more.

[0035] The grounding terminal, upon being connected with a groundingelectrode through plural via-holes, reduces the parasitic inductance andrestrains the attenuation reduction of the SAW filter.

[0036] The SAW filter used in the RF hybrid switch module of thisembodiment includes at least two SAW elements corresponding to the firstand second frequency bands, respectively. FIGS. 7 through 9 are planviews showing mounting conditions and terminal arrangements of the SAWfilters and RF chip components.

[0037] In FIG. 7, SAW filter 31 is disposed on a center of laminatedbody 38. First SAW element 32 and second SAW element 33 are disposedside by side in the longitudinal direction of laminated body 38. Aportion of circuits and filters corresponding to the first frequencyband is formed on a region of the laminated body near first SAW element32. The portion of the circuits and filters is formed of diodes D1 andD2, chip inductors L2 and L3, first transmitting terminal 34, firstreceiving terminal 35, capacitors C1 through C10, and inductors L1 andL4 through L6. The diodes and chip inductors are mounted on thelaminated body, and the capacitors and inductors are formed ofelectrodes.

[0038] A portion of the circuits and filters corresponding to the secondfrequency band is formed in a region of the laminated body near secondSAW element 33. The portion of the circuits and the filters is formed ofdiodes D3 and D4, chip inductors L10 and L11, second transmittingterminal 36, second receiving terminal 37, capacitors C11 through C20and inductors L7 through L9, L12, and L13. The diodes and chip inductorsare mounted on the laminated body, and the capacitors and inductors areformed of electrodes. This arrangement reduces mutual interferencebetween circuits operating at respective frequency bands. Thisarrangement also reduces a coupling between transmitting terminals andreceiving terminals, and thus improves isolation between the terminals.5 In FIG. 8, SAW filter 39 is disposed on a center of laminated body 46.First SAW element 40 and second SAW element 41 are disposed adjacenteach other vertically to the longitudinal direction of laminated body46. Transmitting terminal 42 and receiving terminal 43 for the firstfrequency band are disposed apart from each other on an area near thefirst SAW element. Transmitting terminal 44 and receiving terminal 45for the second frequency band are disposed apart from each other on anarea near the second SAW element. A conductor such as another terminalmay be formed between the transmitting terminal and receiving terminal.The transmitting terminal and receiving terminal may be formed apartfrom each other at edges of the laminated body. This reduces a couplingbetween the transmitting terminals and receiving terminals, and thusimproves isolation between them.

[0039] In FIG. 8, a portion of circuits and filters corresponding to thefirst frequency band is formed in a region of the laminated body nearfirst SAW element 40. The portion of the circuits and the filters isformed of diodes D1 and D2, chip inductors L2 and L3, capacitors C1through C10 and inductors L1, L4 through L6. The diodes and chipinductors are mounted on the laminated body, and the capacitors andinductors are formed of electrodes. A portion of the circuits andfilters corresponding to the second frequency band is formed in a regionof the laminated body near second SAW element 41. The portion of thecircuits and filters is formed of diodes D3 and D4, chip inductors L10and L11, capacitors C11 through C20 and inductors L7 through L9, L12,and L13. The diodes and chip inductors are mounted on the laminatedbody, and the capacitors and inductors are formed of electrodes. Thisarrangement reduces mutual interference between circuits operating atrespective frequency bands, and thus improves isolation between them.

[0040] In FIG. 9, SAW filter 47 is disposed at one side on laminatedbody 54. First SAW element 48 and second SAW element 49 are disposedadjacent each other vertically to the longitudinal direction oflaminated body 54. Transmitting terminal 50 and receiving terminal 51for the first frequency band are formed apart from each other on an areanear first SAW element 48 on the laminated body. Transmitting terminal52 and receiving terminal 53 for the second frequency band are formedapart from each other on an area near second SAW element 47 on thelaminated body. A conductors such as another terminal may be formedbetween the transmitting terminal and receiving terminal. Thetransmitting terminal and receiving terminal may be formed apart fromeach other at respective edges of the laminated body. This arrangementreduces a coupling between the transmitting terminals and receivingterminals, and thus improves isolation between them.

[0041] In FIG. 9, a portion of circuits and filters corresponding to thefirst frequency band is formed in a region of the laminated body nearfirst SAW element 48. The portion of the circuits and the filters isformed of diodes D1 and D2, chip inductors L2 and L3, capacitors C1through C10 and inductors L1, L4 through L6. The diodes and chipinductors are mounted on the laminated body, and the capacitors andinductors are formed of electrodes. A portion of the circuits andfilters corresponding to the second frequency band, is formed in aregion of the laminated body near second SAW device 47. The portion ofthe circuits and the filters is formed of diodes D3 and D4, chipinductors L10 and L11, capacitors C11 through C20 and inductors L7through L9, L12, and L13. The diodes and chip inductors are mounted onthe laminated body, and the capacitors and inductors are formed ofelectrodes. This arrangement reduces mutual interference betweencircuits operating at respective frequency bands, and thus improvesisolation between them.

[0042]FIG. 10 shows an internal structure of the laminated body of theRF hybrid switch module in accordance with the embodiment of the presentinvention. The laminated body is formed of dielectric layers 55 athrough 55 h. Capacitor C4 is formed of a capacitance between capacitorelectrodes 56 and 57. Terminal C4 a of the capacitor near the groundshown in the equivalent circuit of FIG. 2 is formed of electrode 57which is nearer than electrode 56 to grounding electrode 60. Thisarrangement reduces a parasitic capacitance between electrode 56 andgrounding electrode 60, and thus provides an RF hybrid switch moduleoperating efficiently.

[0043] Electrode 57 near grounding electrode 60 has a larger size thanelectrode 56. This arrangement reduces a parasitic capacitance betweenelectrode 56 and grounding electrode 60. This arrangement furtherprovides a capacitor having a stable capacitance which is not affectedseriously by a positional deviation in printing or laminating during itsmanufacturing.

[0044] Adjoining spiral electrodes 58 and 59 in the laminated body forminductors L5 and L1 shown in the equivalent circuit of FIG. 2,respectively. The spiral inductors are formed in the same spiraldirection in consideration for a signal pass. This arrangement reducesinfluence of coupling between their spiral patterns.

[0045] An electrode relating to a transmitting function may be formed ona dielectric layer which is farther from the grounding electrode than adielectric layer on which an electrode pattern relating a receivingfunction is formed. This arrangement reduces a coupling betweentransmitting circuits and receiving circuits, and shorten electricalwiring, thus providing an RF hybrid switch module operating efficiently.

INDUSTRIAL APPLICABILITY

[0046] The present invention provides a small radio frequency (RF)hybrid switch module operating efficiently used in a mobilecommunication device such as a cellular phone. The module includes adividing circuit, a switching circuit, a low pass filter, and a surfaceacoustic wave (SAW) filter corresponding to plural frequency bandsintegrated..

Reference Numerals

[0047]1-5 Terminal

[0048]6, 7 Controlling Terminal

[0049]8 Dividing Circuit

[0050]9, 10 Switch

[0051]11, 13 Low Pass Filter (LPF)

[0052]12, 14, 15, 31, 39, 47 Surface Acoustic Wave (SAW) Filter

[0053]16 Chip Component

[0054]17, 38, 46, 54 Laminated Body

[0055]17 a, 17 b Laminated Body

[0056]18, 28, 60 Grounding Electrode

[0057]19-22 Grounding Terminal

[0058]23 a-26 a Via-Hole

[0059]23 b-26 b Via-Hole

[0060]29 SAW Resonator

[0061]30 Parasitic Inductance

[0062]32, 33, 40, 41, 48, 49 SAW Element

[0063]34, 36, 42, 44, 50, 52 Transmitting Terminal

[0064]35, 37, 43, 45, 51, 53 Receiving Terminal

[0065]55 a-55 h Dielectric Layer

[0066]56, 57 Electrode For Capacitor

[0067]58, 59 Spiral Pattern

1. A radio frequency (RF) hybrid switch module for switching betweensignals of a plurality of frequency bands, comprising: a dividingcircuit; a switching circuit; a low pass filter (LPF); an electrodepattern forming at least a portion of said dividing circuit, switchingcircuit, and LPF; a laminated body including a plurality of dielectriclayers, said electrode pattern being formed on at least one of saiddielectric layers; a surface acoustic wave (SAW) filter corresponding tothe frequency bands, having a grounding port, being mounted on saidlaminated body; a diode mounted on said laminated body, for forming aportion of said switching circuit; a grounding electrode formed in saidlaminated body; and a via-conductor directly connecting said groundingport of said SAW filter.
 2. The RF hybrid switch module of claim 1,wherein said grounding electrode is formed on a farthest dielectriclayer of said dielectric layers from a dielectric layer having said SAWfilter mounted thereon of said laminated body is mounted, or on adielectric layer near said farthest dielectric layer.
 3. The RF hybridswitch module of claim 1, wherein said grounding port is directlyconnected with said grounding electrode through a plurality of saidvia-conductors.
 4. The RF hybrid switch module of claim 1, wherein thefrequency bands include first and second frequency bands, wherein atleast one of said dividing circuit, switching circuit, and LPF includesfirst and second portions corresponding to the first and secondfrequency bands, respectively, wherein said SAW filter includes: a firstSAW element corresponding to the first frequency band; and a second SAWelement corresponding to the second frequency band, said first andsecond SAW elements being disposed adjacent each other substantially ona center of said laminated body, wherein said first portion is disposedin a first region of said laminated body near said first SAW element,and wherein said second portion is disposed in a second region of saidlaminated body near said second SAW element.
 5. The RF hybrid switchmodule of claim 4, further comprising: a first transmitting terminal forthe first frequency band, being formed in said first region; a firstreceiving terminal for the first frequency band, being formed in saidfirst region at an opposite side to said first transmitting terminal; asecond transmitting terminal for the second frequency band, being formedin said second region; and a second receiving terminal for the secondfrequency band, being formed in said second region at an opposite sideto said second transmitting terminal.
 6. The RF hybrid switch module ofclaim 1, further comprising: a first transmitting terminal formed onsaid laminated body; a first receiving terminal formed on said laminatedbody; a second transmitting terminal formed on said laminated body; anda second receiving terminal formed on said laminated body, wherein thefrequency bands include first and second frequency bands, wherein saidfirst transmitting terminal and said first receiving terminal correspondto the first frequency band, wherein said second transmitting terminaland said second receiving terminal correspond to the first frequencyband, wherein said SAW filter includes: a first SAW elementcorresponding to the first frequency band; and a second SAW elementcorresponding to the second frequency band, said first and second SAWelements disposed adjacent to each other substantially on a center ofsaid laminated body, wherein said first transmitting terminal and saidfirst receiving terminal are formed in a first region of said laminatedbody near said first SAW element, and wherein said second transmittingterminal and said second receiving terminal are formed in a secondregion of said laminated body near said second SAW element.
 7. The RFhybrid switch module of claim 6, further comprising: a first conductorformed on said laminated body between said first transmitting terminaland said first receiving terminal; and a second conductor formed on saidlaminated body between said second transmitting terminal and said secondreceiving terminal.
 8. The RF hybrid switch module of claim 6, whereinsaid first transmitting terminal and said first receiving terminal areformed near respective edges of said laminated body, said edges beingopposite to each other in a disposing direction of said first and secondSAW elements, and wherein said second transmitting terminal and saidsecond receiving terminal are formed near respective edges of saidlaminated body, said edges being opposite to each other in the disposingdirection of said first and second SAW elements.
 9. The RF hybrid switchmodule of claim 6, wherein at least one of said dividing circuit,switching circuit, and LPF includes: a first portion formed in saidfirst region, corresponding to the first frequency band; and a secondportion formed in said second region, corresponding to the secondfrequency band.
 10. The RF hybrid switch module of claim 1, furthercomprising: a first transmitting terminal formed on said laminated body;a first receiving terminal formed on said laminated body; a secondtransmitting terminal formed on said laminated body; and a secondreceiving terminal formed on said laminated body, wherein the frequencybands include first and second frequency bands, wherein said firsttransmitting terminal and said first receiving terminal correspond tothe first frequency band, wherein said second transmitting terminal andsaid second receiving terminal correspond to the first frequency band,wherein said SAW filter includes: a first SAW element corresponding tothe first frequency band; and a second SAW element corresponding to thesecond frequency band, said first and second SAW elements being disposedadjacent to each other on a side of said laminated body in parallel withsaid side, wherein said first transmitting terminal and said firstreceiving terminal are formed in a first region of said laminated bodynear said first SAW element, and wherein said second transmittingterminal and said second receiving terminal are formed in a secondregion of said laminated body near said second SAW element.
 11. The RFhybrid switch module of claim 10, further comprising: a first conductorformed on said laminated body between said first transmitting terminaland said first receiving terminal; and a second conductor formed on saidlaminated body between said second transmitting terminal and said secondreceiving terminal.
 12. The RF hybrid switch module of claim 10, whereinsaid first transmitting terminal and said first receiving terminal areformed near respective edges of said laminated body, said edges beingopposite to each other in a disposing direction of said first and secondSAW elements, wherein said second transmitting terminal and said secondreceiving terminal are formed near respective edges of said laminatedbody, said edges being opposite to each other in the disposing directionof said first and second SAW elements.
 13. The RF hybrid switch moduleof claim 10, wherein at least one of said dividing circuit, switchingcircuit, and LPF includes: a first portion formed in said first region,corresponding to the first frequency band; and a second portion formedin said second region, corresponding to the second frequency band. 14.The RF hybrid switch module of claim 1, wherein at least one of saiddividing circuit, switching circuit, and LPF includes: a first capacitorelectrode on a first dielectric layer of said dielectric layers; and asecond capacitor electrode on a second dielectric layer of saiddielectric layers, said second dielectric layer being nearer to saidgrounding electrode than said first dielectric layer.
 15. The RF hybridswitch module of claim 1, wherein said first capacitor electrode has adifferent size from said second capacitor electrode.
 16. The RF hybridswitch module of claim 15, wherein said second capacitor electrode islarger than said first capacitor electrode.
 17. The RF hybrid switchmodule of claim 1, wherein said electrode pattern includes spiralelectrode patterns formed in an identical spiral direction, said spiralelectrode patterns adjoining to each other.
 18. The RF hybrid switchmodule of claim 1, wherein said electrode pattern includes: a firstelectrode pattern relating to a receiving function of said dividingcircuit, switching circuit, and LPF; and a second electrode patternrelating to a transmitting function of said dividing circuit, switchingcircuit, and LPF, wherein said first electrode pattern is formed on afirst dielectric layer of said dielectric layers, wherein said secondelectrode pattern is formed on a second dielectric layer of saiddielectric layers, said second dielectric layer being farther from saidgrounding electrode than said first dielectric layer.